Various seismic energy sources are known and used. Some act as "point" sources, others as "linear" sources. An example of a point source is an explosive cartridge, an example of a linear source is a long strand of detonating fuse such as Primacord, manufactured by Ensign-Bickford, Inc. of Simsbury, Connecticut. For best coupling to the ground such linear souces are desirably buried a few feet below the earth's surface. A vibratory plow, such as manufactured by the Charles Machine Works, Inc. of Perry Oklahoma, can be used for mechanically burying the Primacord without appreciably disturbing the earth. In practice, the linear sources are grouped in a desirable pattern depending on well-known consideration related to the particular site being seismically explored. In the vicinity of the "shooting site" are also deployed strings of seismic detectors or geophones. One or more of the linear energy sources are detonated and the resulting reflected seismic signals are detected by the detectors for recording on a suitable medium, typically magnetic tape. Customarily the geophones are set out on the surface of the earth, however, to minimize the detection of background noise, the geophones could also be buried a short distance below the earth's surface. The deployment and the burial of the geophones would be time consuming operations which would add considerably to the overall cost of seismic exploration.
After a series of seismic shots are made at the first shooting site, the seismic crew repeats the steps of burying the linear seismic sources and of deploying the geophones at another site, and the steps of shooting and recording are again repeated.
Although subsurface burial of the Primacord is mechanized, the relocation of the groups of geophones from detecting site to detecting site still requires considerable hand labor in the preparation of the detecting site and the deployment of the detectors.
It is a general object of the present invention to provide a new method of land seismic prospecting which minimizes the amount of hand labor required. The invention also provides new apparatus useful in carrying out the method.